A semiconductor die package uses a package core to hold one or more dice and a cover to protect the die or dice from the contaminants and impact. The die inside the package is mounted to a core or a substrate. The package core can provide stiffness and structure to the package. The package core may also provide thermal heat dissipation, power delivery and signal integrity benefits, depending on the particular package type and its application.
In cored packages electrical paths are needed from one side of the core (die side) to the other (board side). The core or substrate includes conductive paths so that the die can make electrical connections on one side of the core though the core to the outside of the package and connect to a printed circuit board or some other substrate, material, or device for power and data signals. The core may also provide a geometric transformation from the compact electrical contact configuration of a silicon die to the larger scale of the contacts on a printed circuit board that the package is mounted on.
Cylindrical, plated, filled, and plugged through holes are used to transfer power and signals through package cores. There are a variety of different types of conductive paths used with different types of package substrates and cores. The different paths have different benefits and include PTHs (Plated Through Holes), and LTHs (Laser Through Holes), among others.
As semiconductor dies become smaller and require more power, through holes or vias must carry more current or carry faster signals in less space at less cost to build. Faraday Cage-like structures have been shown for through holes, but they must be constructed as spaced apart PTHs. However, due to the large gaps between the PTHs, this structure requires a large area on the core and is rarely used in products.